Conventional ultrasonic diagnostic apparatuses generally employ a method called delay-and-sum method as a beamforming method for received ultrasound (for example, Non-Patent Literature 1).
FIG. 21 schematically shows the conventional delay-and-sum method.
A conventional ultrasonic diagnostic apparatus includes: a plurality of receiving elements 2101 that receive ultrasound; a plurality of delay units 2102 provided to the respective receiving elements 2101 to delay signals; and an addition unit 2103 that sums output signals of the delay units 2102.
In the delay-and-sum method, a signal received by each of the receiving elements 2102 is delayed for each element by the delay unit 2102 corresponding to the element. After delaying signals, the addition unit 2103 adds the delayed signals together to generate an addition result (signal 2103x) that is a sum of the signals.